This invention relates to means which may be connected to the windings of an electric motor, such as an overhead ceiling fan permanent split capacitor (PSC) motor, externally of the motor housing so as to permit the direction of rotation of the motor to be selectively reversed and so as to permit multiple speed operation of the motor in either direction of rotation.
In certain motor applications, such as in PSC overhead ceiling fan applications, it is desirable that the motor be capable of operating in either direction (i.e., either clockwise or counter-clockwise) so that the ceiling fan can be operated to move air in an upwardly or downwardly direction, as desired. Typically, the reversal of the direction of rotation of the motor shaft is accomplished by changing the connection point across opposite sides of the run capacitor in series with the auxiliary winding of the motor. However, many such non-reversible motors used for overhead ceiling fan applications were manufactured as multi-speed motors which had a plurality of windings connected in series with tapping points between the various main windings which could be selectively tapped by means of a multiple position speed selector switch. Certain of the motors had a different number of turns in one main winding than in the other main winding such that when the motor was operated in one of its preselected operational speeds, the motor was operated with unbalanced windings (i.e., unbalanced physical turns).
While the operation of a motor with unbalanced windings did not pose any significant problems at any of its normal operating speeds, it was not practical to readily convert such unbalanced, multiple speed non-reversible motors for reversible operation utilizing a motor reversing switch which reversed the connection of the leads to the main windings. In most instances, it was necessary to open up the motor housing and to add an additional lead wire which required a considerable expenditure of time and money to convert "non-reversible" motors to reversible motors.
There has been a long standing need for apparatus or means which can be readily added to a multiple speed, non-reversible motor so as to convert the motor to a multiple speed, reversible electric motor.